1. Field of the Invention
The present invention relates to a structure for mounting a slip joint on the body of a vehicle for use in a seat belt system with which the vehicle is equipped.
2. Description of Related Art
As shown in FIG. 8, a conventional slip joint 80 has a form in which a lower portion 84 is bent relative to an upper portion 82, a bolt insertion hole 86 being provided in the upper portion 82 and an elongated hole 90 through which a webbing 88 is passed such that the webbing 88 is slidably supported thereby being provided in the lower portion 84. The slip joint 80 is slidably mounted on the side wall 94 of a vehicle with the aid of a bolt 92. In such a conventional structure for mounting a slip joint, however, when the webbing 88 provided as shown in FIG. 8 is pulled out against the take-up force exerted by a take-up apparatus (not shown), clockwise moment A acts on a portion adjacent to the upper end of the upper portion 82 of the slip joint 80 to produce a pinching force F which acts on the slip joint 80 such as to press it against the side wall of the vehicle. The magnitude of the pinching force F is proportional to the moment A produced by resultant force F3 of a take-up force F1 and a pulling-out force F2 of the webbing 88. The moment A is determined by the product of the resultant force F3 and the moment arm A1 which intersects at right angles an extension of the line representing the resultant force F3 and which passes through a point adjacent to the upper end of the slip joint 80.
If a seat occupant around which the webbing is fastened moves in the lengthwise direction of the vehicle, the slip joint 80 cannot be easily rotated around the bolt 92 and so does not follow the movement of the portion of the webbing placed around the seat occupant, resulting in an unpleasant feeling when the webbing is pulled out.